Feed intake and digestibility are important indicators for sufficient nutrient supply, but they can be assessed only to a limited extent in horses on pasture. In horses, feed intake is embedded in a complex behavioural pattern of searching, selecting, chewing and almost constant movement called foraging. The objectives of this study were to estimate organic matter intake (OMI) and organic matter digestibility (OMD) in six horses, 24 h/day on pasture, based on plant alkanes and synthetic n-hexatriacontane (C36) excretion. A multi-compartmental model was fitted to the marker excretion and the C36 mean retention time (MRT) was estimated. The travelling activity influences the intestinal passage and digestion of the forage. For this reason, the travelled distances were tracked during the daylight hours (i.e., 13 h/day) by the global positioning system (GPS). The C36 MRT was 17.5 h based on an excretion curve, in which all horses were considered. Fitting individual excretion curves was less successful due to limited data points available for each horse. Depending on the plant marker, an OMI of 1.4 to 2.8% of body weight (BW)/day was estimated, which is analogous to a dry matter intake (DMI) of 1.5 to 3.1% of BW/day. The estimated OMD ranged from 0.45 to 0.68, dry matter digestibility (DMD) analogously from 0.39 to 0.65. The estimates obtained using n-nonacosane (C29), followed by those obtained using n-hentriacontane (C31), seemed to be the most plausible compared to the literature. Using C29, a feed intake of 2.5% of BW/day (group) or 2.1% of BW/day (individuals) was estimated on organic matter basis, which was 2.7% of BW/day or 2.3% of BW/day on dry matter basis. An OMD of 0.64 and a DMD of 0.61 was estimated using C29. Individually travelled distances ranged from 0.09 to 4.64 km in 1 h with differences detected among the days (p < 0.01), but not among the hours monitored within a day. Despite clear limitations, the methods seemed to be reliable to assess feed intake on pasture and to track movement activity. In modern husbandry systems, foraging should be as much unrestricted as possible to satisfy natural behavioural needs.
Alzheimer´s disease is a neurodegenerative disease with high global prevalence and no cure available. It is known that the microbiota-gut-brain-axis plays a role in the pathogenesis, but the pathways are not fully understood yet. To elucidate the role of dietary fibre supplementation on this axis in a 5xFAD mouse model of Alzheimer´s disease, a feeding trial with an inulin supplement was conducted. At the start (Basis, n = 11) and after 7 weeks with (AD + F; n = 15) and without (AD; n = 15) supplementation, the mice were sacrificed and the following samples were taken: ingesta for 16 S rRNA sequencing and short-chain fatty acid (SCFA) analysis, and brain tissue for amyloid-beta staining and proteome analysis. The microbiota patterns in stomach, small intestine, caecum and colon differed between AD and AD + F. SCFA concentrations were significantly higher in group AD + F as compared to AD and Basis. In the AD mice, plaque load was significantly increased as compared to Basis, while a reduction in AD + F as compared to AD was observed. The brain proteome also differed between AD + F and AD, indicating a beneficial effect of the inulin supplementation, possibly mediated in part by microbial acetate. Since prebiotic substances like inulin are also part of human diets, this should be investigated further in the translational context.
The use of legume grains as a protein and energy source in broiler rations promotes regional feed production and offers ecological and economic advantages over imported feed. The feeding value of legume grains can be limited by antinutritional factors. Three consecutive experiments were conducted to determine precaecal amino acid (AA) digestibility of native (experiment 1), dehulled (experiment 2) or toasted and dehulled lupin and pea grains (experiment 3). For each experiment, the grains were ground through 2- or 3-mm sieves, mixed into experimental diets and pelleted. The digestibility of AA was estimated by linear regression using ileal digesta samples of broiler chickens 34 d of age. Total precaecal AA digestibility of 2-mm and 3-mm ground lupin grains was 83 and 85
The transformation of hypoglycin A (HGA), hypoglycin B (HGB), and methylene cyclopropyl glycine (MCPrG) in ruminal fluid batch cultures was investigated, and the effect of these toxins on the batch culture microorganisms using microbial metabolites was measured. An experiment was conducted using ovine ruminal fluid batch cultures and the ANKOM RF Gas Production System over four runs, each with an incubation period of 48 h. The fermenters contained 200 mg of (i) a substrate mixture (80% cellulose, 20% starch; CSM), (ii) CSM and 1.5 mL of a solution of pure toxins (a mixture of 500 ng/mL HGA and MCPrG each; PCM), or (iii) CSM and 100 mg sycamore maple seeds (SMS). Each fermenter contained 30 mL of inoculum (ruminal fluid and buffer, 1:2 v/v). For control, autoclaved ruminal fluid was incubated with CSM, PCM, and SMS, respectively. Samples were taken from the liquid phase of the fermenters and analyzed using liquid chromatography–tandem mass spectrometry (LC/MS-MS) for sycamore maple toxins and metabolites. Microbial activity was assessed using gas production, short chain fatty acids, and NH3 concentration. Additionally, pH and redox potentials were measured. In PCM, HGA and MCPrG concentrations rapidly decreased (p < 0.05), and were not measurable anymore after a 24 h incubation period. In SMS, the initial concentrations were 4.7 ± 1.4 µg/mL HGA, 19.9 ± 5.41 µg/mL HGB, and 1.2 ± 0.33 µg/mL MCPrG. In SMS, HGA increased in 24 h, coincidently to a decrease in HGB concentration (p < 0.05). We modeled a rapid conversion of HGB to HGA, accompanied by progressive HGA transformation. The concentration of MCPrG was constant until 4 h and decreased afterwards (p < 0.05). In SMS incubations, HGA and MCPrG concentrations of 5.6 ± 1.5 and 0.32 ± 0.090 µg/mL remained after 48 h, respectively. The HGB to HGA conversion and transformation of HGA and MCPrG also occurred in autoclaved ruminal fluid. Gas production and microbial metabolite concentrations were higher in SMS compared to CSM and PCM (p < 0.05), as the seeds were used as an additional substrate by the batch culture microorganisms.
The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO 2 /FiO 2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.
The objectives of the study were to examine the effect of an antibiotic solution applied in the Streptomyces griseus protease method (SGPM) and the effect of carbohydrases in SGPM on the effective crude protein (CP) degradation (ED) with reference to in sacco ED. For this purpose, the ruminal CP degradation of rapeseed meal, dried distillers’ grains with solubles, wheat grain, corn grain, corn silage, grass silage and partial crop field pea silage was determined in sacco using three rumen-fistulated dairy cows and in vitro using SGPM. The impact of the antibiotic solution on CP degradation by S. griseus protease was investigated by supplementing SGPM with Penicillin–Streptomycin solution to reduce microbial mass proliferation during incubation. The carbohydrase α-amylase or Viscozym® L (cell wall-degrading enzyme mixture) was added to the SGPM at four different doses simultaneously as a co-incubation to improve feed protein accessibility. For most feedstuffs, ED was lower when the antibiotic solution was used in SGPM (p < 0.05). The use of an antibiotic solution in the SGPM is recommended to standardize the SGPM. The in sacco ED values were significantly underestimated by the SGPM and by the SGPM with co-incubated carbohydrase (p < 0.05). Co-incubation of S. griseus protease and carbohydrase was not successful in reducing the differences to the in sacco CP degradation.
Concentrations of starch, mono- and disaccharides, fructans, hemicellulose and cellulose were analysed in feed and gastric digesta of horses in relation to acid insoluble ash as a marker indigestible in the stomach. Twenty-four horses were allocated to pasture 24 h/d (PST; n = 4), hay ad libitum (HAY; n = 8), hay ad lib. and oats at 1 g starch/kg body weight (BWT)/meal (OS1; n = 6) and hay ad lib. and oats at 2 g starch/kg BWT/meal (OS2; n = 5). One horse was excluded from the analysis. The horses were fed the ration a minimum of 34 days. Following euthanasia and dissection, digesta was sampled from Pars nonglandularis (PNG) and Pars glandularis (PG). Oat starch concentration in gastric digesta decreased from 309 to 174 g/kg dry matter (DM) in OS1 (44 %-reduction) and from 367 to 261 g/kg DM in OS2 (29 %-reduction) (P < 0.001). Glucose, fructose and sucrose disappeared from gastric digesta distinctly more in PST, HAY and OS1 than in OS2. In PST and HAY, sucrose concentration was completely cleared (P < 0.001). The concentration of fructans was reduced predominantly in PST (84 %-reduction) and HAY (54 %-reduction), mainly in the PNG (P < 0.05). Fructan degradation did not occur in the high-starch diet (OS2). Some evidence for fibre degradation was observed in PST (P < 0.01). Soluble carbohydrates disappear from the stomach dependent on the type of ration, which may lead to changes in the composition of the gastric microbial community and the endogenous response.
For protein evaluation of feedstuffs for ruminants, the Streptomyces griseus protease test provides a solely enzymatic method for estimating ruminal protein degradation. Since plant proteins are often structured in carbohydrate complexes, the use of carbohydrase during the test might improve its accuracy. It is advisable to co-incubate protease and carbohydrase, risking that the carbohydrase activity is reduced under the influence of the protease. The present study was conducted to investigate this impact by using α-amylase or the multi-enzyme complex Viscozym® L as carbohydrase. The detection of active protease was determined fluorescence photometrically using internally quenched fluorogenic substrates (IQFS). Cellulose, pectin, and starch degradation were determined spectrophotometrically using 3,5-dinitro salicylic acid as a colorimetric agent. The Streptomyces griseus protease mixture proved to be active for the selected IQFS immediately after the start of measurements (p < 0.05). Starch hydrolysis catalyzed by α-amylase or Viscozym® L, respectively, was decreased by co-incubation with protease mixture by maximal 3% or 37%, respectively, at 5 h incubation time (p > 0.05). Pectin and cellulose hydrolysis catalyzed by Viscozym® L, respectively, was not significantly influenced by co-incubation with a protease mixture (p > 0.05). Although a decrease in carbohydrase activity during co-incubation with Streptomyces griseus protease occurred, it was only numerical and might be counteracted by an adapted carbohydrase activity.
Background With the emergence of new subvariants, the disease severity of Severe Acute Respiratory Syndrome Coronavirus-2 has attenuated. This study aimed to compare the disease severity in patients hospitalized with omicron variant infection to those with influenza infection. Methods We compared data from the multicenter observational, prospective, epidemiological “CORONA Germany” (Clinical Outcome and Risk in hospitalized COVID-19 patients) study on patients infected with Severe Acute Respiratory Syndrome Coronavirus-2 to retrospective data on influenza infection cases from November 2016 to August 2022. Severe Acute Respiratory Syndrome Coronavirus-2 cases were classified as wild-type/delta variant before January 2022, or omicron variant from January 2022 onward. The primary outcome was in-hospital mortality, adjusted for age, gender, and comorbidities. Results The study included 35,806 patients from 53 hospitals in Germany, including 4,916 patients (13.7%) with influenza infection, 16,654 patients (46.5%) with wild-type/delta variant infection, and 14,236 patients (39.8%) with omicron variant infection. In-hospital mortality was highest in patients with wild-type/delta variant infection (16.8%), followed by patients with omicron variant infection (8.4%) and patients with influenza infection (4.7%). In the adjusted analysis, higher age was the strongest predictor for in-hospital mortality (age 80 years vs. age 50 years: OR 4.25, 95% CI 3.10–5.83). Both, patients with wild-type/delta variant infection (OR 3.54, 95% CI 3.02–4.15) and patients with omicron variant infection (OR 1.56, 95% CI 1.32–1.84) had a higher risk for in-hospital mortality than patients with influenza infection. Conclusion After adjusting for age, gender and comorbidities, patients with wild-type/delta variant infection had the highest risk for in-hospital mortality compared to patients with influenza infection. Even for patients with omicron variant infection, the adjusted risk for in-hospital mortality was higher than for patients with influenza infection. The adjusted risk for in-hospital mortality showed a strong age dependency across all virus types and variants. Trial registration number NCT04659187 .
This study was conducted to examine effects of ensiling, toasting or ensiling plus toasting in partial-crop field peas and faba beans harvested each with 375 g dry matter/kg (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie (BBCH) scale 79 and 81, respectively) on gas production and post-ruminal crude protein (PRCP) concentration by in vitro incubation in ruminal fluid batch-cultures. The silages made from partial-crop field peas and faba beans (Rostock Model Silages) had a pH of 4.3 and 4.6, respectively, and were not typically lactic acid dominated. The silages remained stable after opening for 100 h (peas) and 168 h (faba beans). Toasting was simulated in a drying oven at 160 °C for 60 min. Post-incubation pH and gas accumulation profiles were little affected by treatment. Ensiling did not alter effective PRCP. Toasting and ensiling plus toasting increased effective PRCP up to 25 and 20%-points in peas and up to 35 and 11%-points in faba beans, respectively. Ensiling increased non-protein nitrogen and soluble protein concentration, whilst toasting decreased soluble protein. Significant correlations existed between protein fraction B3 (neutral detergent-insoluble protein) and effective PRCP (r≥0.84; P<0.05) and fraction C (acid detergent-insoluble protein) and effective PRCP (r≥0.79; P<0.05). Ensiling and toasting both decreased arginine and lysine levels. It was concluded that partial-crop peas and faba beans with BBCH 79 and 81, respectively, can provide readily available nutrients and high-quality fibre in the residual plant. However, preserving by ensiling required balance between the reduction of non-protein nitrogen and fermentability characteristics. Toasting reduced protein solubility and increased PRCP, but it was not clear if PRCP was usable for ruminants or was partially bound into Maillard polymers.
It has recently been shown that von Willebrand factor (VWF) multimers contribute to immunothrombosis in Coronavirus disease 2019 (COVID-19). Since COVID-19 is associated with an increased risk of autoreactivity, the present study investigates, whether the generation of autoantibodies to ADAMTS13 contributes to this finding. In this observational prospective controlled multicenter study blood samples and clinical data of patients hospitalized for COVID-19 were collected from April to November 2020. The study included 156 individuals with 90 patients having confirmed COVID-19 of mild to critical severity. 30 healthy individuals and 36 critically ill ICU patients without COVID-19 served as controls. ADAMTS13 antibodies occurred in 31 (34.4%) COVID-19 patients. Antibodies occurred more often in critically ill COVID-19 patients (55.9%) than non-COVID-19 ICU patients and healthy controls (5.6% and 6.7%; p < 0.001), respectively. Generation of ADAMTS13 antibodies in COVID-19 was associated with lower ADAMTS13 activity (56.5%, interquartile range (IQR) 21.25 vs. 71.5%, IQR 24.25, p = 0.0041), increased disease severity (severe or critical in 90% vs. 62.3%, p = 0.019), and a trend to higher mortality (35.5% vs. 18.6%, p = 0.077). Median time to antibody development was 11 days after first positive SARS-CoV-2-PCR specimen. Gel analysis of VWF multimers resembled the constellation in patients with TTP. The present study demonstrates for the first time, that generation of ADAMTS13 antibodies is frequent in COVID-19, associated with lower ADAMTS13 activity and increased risk of an adverse disease course. These findings provide a rationale to include ADAMTS13 antibodies in the diagnostic workup of SARS-CoV-2 infections.
The use of enrichment and bedding materials in pig husbandry intends to comply with the animals' behavioural needs to perform natural exploratory behaviour, which is strongly connected to foraging behaviour. It can thus be assumed that pigs will ingest a certain material quantity possibly posing a risk to animal health and food safety as previous studies identified contaminants in enrichment and bedding materials. However, risk assessment requires knowledge about the effective amount of ingested material. Voluntary material intake of pigs with free access to peat and disinfectant powder was estimated by measuring the tissue levels of toxic metals originating from the respective materials in 28 pigs (seven groups, n = 4) via inductively coupled plasma mass spectrometry and comparing the results to tissue levels of pigs fed with known amounts of metals. Additionally, as markers of consumption, n-alkanes and acid insoluble ash naturally occurring in the materials and titanium dioxide, added as an external marker to disinfectant powder, were analysed in pigs' faeces. Tissue levels of toxic metals as well as marker analyses in pigs' faeces could prove material consumption. Results revealed mean voluntary intake levels of peat and disinfectant powder by pigs up to 7% and 2% of the daily ration. Hence, a transfer of contained toxic metals into the food chain might occur. Although current maximum levels for toxic elements in animal tissues were not exceeded due to dietary inclusion of peat or disinfectant powder, dietary exposure through food of animal origin should be reduced to a possible minimum. This applies specifically for elements, where no health-based guidance values for humans could have been derived (e.g. arsenic). Thus, labelling guidelines for enrichment and bedding materials can be a perspective to limit the entry of toxic metals and trace elements into the environment.
Effective degradation (ED) of crude protein (CP) was estimated in vitro at 0.02, 0.05 and 0.08 h−1 assumed ruminal passage rates for a total of 40 feedstuffs, for which in situ ED was available and used as reference degradation values. For this, the Streptomyces griseus protease test was used. The differences between in vitro CP degradation and the in situ CP degradation values were lowest in legume grains and highest in cereal by-products and barley. The differences between in situ and in vitro ED were expressed using a degradation quotient (degQ), where degQ = (EDin vitro − EDin situ)/EDin situ. Among the tested feedstuffs, eight specific clusters were identified according to degQ for the assumed passage rates. The feedstuffs clustered in an unspecific way, i.e., feedstuffs of different nutrient composition, origin or treatment did not necessarily group together. Formaldehyde–treated rapeseed meal, soybean meal, wheat, a treated lupin, sunflower meal and barley could not be assigned to any of the clusters. Groupwise degradation (range of degQ for assumed passage rates are given in brackets) was detected in grass silages (−0.17, −0.11), cereal by-products together with sugar beet pulp (−0.47, −0.35) and partly in legume grains (−0.14, 0.14). The clustering probably based on different specific nutrient composition and matrix effects that influence the solubility of feed protein and limit the performance of the protease. The matrix can be affected by treatment (chemically, thermally or mechanically), changing the chemical and physical structure of the protein within the plant. The S. griseus protease test had reliable sensitivity to reflect differences between native feedstuffs and treatments (thermally or chemically) that were found in situ. The in situ results, however, are mostly underestimated. The clustering results do not allow a clear conclusion on the groupwise or feed-specific use of carbohydrate-degrading enzymes as pre- or co-inoculants as part of the S. griseus protease test and need to be tested for its potential to make this test more conform with in situ data.
ZusammenfassungDie Leitlinienaktualisierung zeigt die Vorteile sowie die Grenzen der NIV bei der Behandlung von akutem Atemversagen im klinischen Alltag und bei unterschiedlichen Indikationen auf.Die nichtinvasive Beatmung (NIV) hat einen hohen Stellenwert bei der Therapie des hyperkapnischen akuten Atemversagens, da sie die Aufenthaltsdauer und den Krankenhausaufenthalt auf der Intensivstation sowie die Mortalität deutlich reduziert.Patienten mit kardiopulmonalem Ödem und akutem Atemversagen sollten zusätzlich zu notwendigen kardiologischen Eingriffen mit kontinuierlichem positivem Atemwegsdruck (CPAP) und Sauerstoff behandelt werden. Dies sollte bereits präklinisch und in der Notaufnahme erfolgen.Bei anderen Formen des akuten hypoxämischen Atemversagens mit nur leicht bis mäßig gestörtem Gasaustausch (PaO2/FiO2 > 150 mmHg) ergibt sich kein signifikanter Vor- oder Nachteil gegenüber nasaler Sauerstoff-High-Flow-Therapie (HFNO). Bei schweren Formen des ARDS ist die NIV mit einer hohen Rate an Behandlungsversagen und Mortalität verbunden, insbesondere in Fällen mit NIV-Versagen und verzögerter Intubation.Zur Präoxygenierung vor der Intubation sollte NIV verwendet werden. Bei Risikopatienten wird eine NIV empfohlen, um Extubationsversagen zu reduzieren. Im Entwöhnungsprozess von der invasiven Beatmung reduziert NIV das Risiko einer Reintubation bei hyperkapnischen Patienten wesentlich. NIV gilt in der Palliativversorgung als nützlich zur Reduzierung von Dyspnoe und zur Verbesserung der Lebensqualität, hier aber in Konkurrenz zur HFNO, das als komfortabler gilt. Mittlerweile wird die NIV auch im präklinischen Bereich empfohlen, insbesondere bei hyperkapnischem Atemversagen und beim Lungenödem.Bei entsprechender Überwachung auf einer Intensivstation kann NIV auch bei pädiatrischen Patienten mit akuter Ateminsuffizienz erfolgreich eingesetzt werden.
The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.
This study was conducted to determine the effect of ensiling on the nutritive value of partial crop field peas. The field peas were harvested with approximately 500 g dry matter (DM) at a cutting height of 25 cm and ensiled without previous wilting or use of inoculants. In vitro gas production kinetics were determined in ruminal fluid batch cultures. The apparent total tract digestibility of crude nutrients, detergent fibers and gross energy and the content of metabolizable energy and net energy lactation of native and ensiled peas was determined in a digestibility trial with wethers. Microbial nitrogen efficiency was calculated on the basis of allantoin excreted via the urine. The pea silage was characterized by a low pH (4.1) and contained relevant quantities of lactic acid (56.3 g/kg DM) and acetic acid (16.8 g/kg DM). The proportions of crude protein, starch and nitrogen-free extracts were slightly increased in the silage, while the concentrations of fiber fractions decreased. Soluble protein was increased in the silage from 56% to 66% of crude protein due to increasing non-protein nitrogen concentrations. Gas production was higher in ensiled than in native peas (P < 0.001). Apparent digestibility of crude protein and acid ether extract increased in the silage by 3% and 10% points, respectively. Digestibility of crude fiber, neutral detergent fiber and acid detergent fiber decreased by 9%, 6% and 5% points, respectively (P < 0.05). The contents of metabolizable energy and net energy lactation increased by 0.5 and 0.3 MJ/kg DM, respectively (P < 0.05). The microbial nitrogen efficiency tended to be higher in animals that received ensiled partial crop peas (P > 0.05), but strongly depended on individual excretion quantities. In conclusion, ensiling of partial crop field peas with approximately 500 g DM/kg at harvest led to well conserved feed with increased concentrations of nutrients and content of energy.
Legumes such as faba beans have a great potential to create local, independent, and high-quality protein resources for ruminant nutrition. Suitable methods for cost- and energy-effective preservation and protein stabilization against rapid fermentation in the rumen play an important role. Partial crop faba beans harvested with 500 or 708 g dry matter (DM)/kg were ensiled, toasted (160 °C, 60 min), or ensiled and toasted and it was investigated how this affects nutrient composition, protein solubility, carbohydrate fermentation, and in vitro organic matter digestibility (IVOMD). Non-protein nitrogen (NPN) concentrations increased and true protein (TP) concentrations decreased after ensiling, depending strongly on DM concentration of the plant (i.e., on maturity) – in NPN, from 15% to 35% (P < 0.001) and from 16% to 21% of crude protein (CP) (P > 0.05), and in TP, from 85% to 65% and from 83% to 79% of CP with 500 and 708 g DM/kg, respectively (P > 0.05) – whereas concentrations of soluble protein did not increase as much as expected. Toasting reduced soluble protein concentration in native faba beans from 56% to 29% and from 54% to 40% of CP with 500 and 708 g DM/kg, respectively (P < 0.001) and in ensiled faba beans from 58% to 38% and from 60% to 34% of CP with 500 and 708 g DM/kg, respectively, compared to the native material (P < 0.001). Ensiling and toasting slightly affected other crude nutrient or metabolizable energy concentrations, carbohydrate fermentation, and IVOMD.
Background Machine learning (ML) algorithms have been trained to early predict critical in-hospital events from COVID-19 using patient data at admission, but little is known on how their performance compares with each other and/or with statistical logistic regression (LR). This prospective multicentre cohort study compares the performance of a LR and five ML models on the contribution of influencing predictors and predictor-to-event relationships on prediction model´s performance. Methods We used 25 baseline variables of 490 COVID-19 patients admitted to 8 hospitals in Germany (March–November 2020) to develop and validate (75/25 random-split) 3 linear (L1 and L2 penalty, elastic net [EN]) and 2 non-linear (support vector machine [SVM] with radial kernel, random forest [RF]) ML approaches for predicting critical events defined by intensive care unit transfer, invasive ventilation and/or death (composite end-point: 181 patients). Models were compared for performance (area-under-the-receiver-operating characteristic-curve [AUC], Brier score) and predictor importance (performance-loss metrics, partial-dependence profiles). Results Models performed close with a small benefit for LR (utilizing restricted cubic splines for non-linearity) and RF (AUC means: 0.763–0.731 [RF–L1]); Brier scores: 0.184–0.197 [LR–L1]). Top ranked predictor variables (consistently highest importance: C-reactive protein) were largely identical across models, except creatinine, which exhibited marginal (L1, L2, EN, SVM) or high/non-linear effects (LR, RF) on events. Conclusions Although the LR and ML models analysed showed no strong differences in performance and the most influencing predictors for COVID-19-related event prediction, our results indicate a predictive benefit from taking account for non-linear predictor-to-event relationships and effects. Future efforts should focus on leveraging data-driven ML technologies from static towards dynamic modelling solutions that continuously learn and adapt to changes in data environments during the evolving pandemic. Trial registration number : NCT04659187.